The others stared at him in astonishment.

“I know where they hide,” he said. “I know where they nest.”

“How?” hissed Isaac. “Where?” He grasped the avatar’s arm in his excitement, then shocked, withdrew his grasp. He was leaning in close to the avatar’s face, and something of the horror of that visage struck him. He could see the rim of shorn skull just inside the man’s curling skin, drab white, streaked with bloody residue. He could see the gory cable plunge into the intricate fold at the bottom of the hollow in the man’s head, from where his brain had been torn.

The avatar’s skin was dry and stiff and cold, like hanging meat.

Those eyes, with their unchanging expression of concentration and thinly hidden anguish, regarded him.

“All of me have tracked the attacks. I have cross-referenced dates and places. I have found correlations, systematized them. I have factored in the evidence of the cameras and the computing engines whose information I steal, the unexplainable shapes in the night sky, the shadows that do not correspond to any city-race.

“There are complex patterns. I have formalized them. I have discarded possibilities and applied high-level mathematical programmes to the remaining potentialities. With unknown variables, absolute certainty is impossible. But according to the data available, the chance is seventy-eight per cent that the nest is where I say.

“The moths are living in the Glasshouse, above the cactus people, in Riverskin.”

“Damn,” hissed Isaac, after a silence. “Are they animals? Or are they cunning? It’s inspired, whichever. Best damn place I can think of.”

“Why?” said Yagharek unexpectedly.

Isaac and Derkhan looked at him.

“New Crobuzon cactacae ain’t like the Cymek variety, Yag,” said Isaac. “Or rather, they are, and maybe that’s the problem. You’ve dealt with ’em in Shankell, doubtless. You know what they’re like. Our cactus people here are a branch of those same desert cactacae who came north. I don’t know anything about the others, the mountain cactus, up in the steppes, east. But I do know the southern style, and their lifestyle never translated so well up here.” He paused and sighed and rubbed his head. He was exhausted and his head still ached. He had to concentrate, to think through the simmering memories of Lin just behind his eyes. He swallowed hard and continued.

“All that puffed-up hard-man stuff that rules the roost in Shankell starts looking a bit dubious up here. That’s why they built the Glasshouse, you ask my opinion. Have a nasty little bit of the Cymek in New Crobuzon. They got special dispensation in law when the Glasshouse was put up—gods only know what deals they had to cut to get that. Technically it’s an independent country. No entry for anyone without permission, including the militia. They’ve got their own laws in there, their own everything.